1. Field of the Invention
The field of the invention relates generally to transmissions, and more particularly to continuously variable transmissions (CVTs).
2. Description of the Related Art
Embodiments of the CVTs disclosed here can be used in any machine, device, vehicle, etc., where it is desired to adjust the ratio of input speed to output speed. A bicycle is one such application. The drivetrain of a bicycle typically consists of pedals coupled to cranks for driving a crankshaft, which is received in, and supported by, frame members of the bicycle. The crankshaft is coupled to a sprocket that transfers power to the rear wheel of the bicycle by a chain. A cog at the rear wheel receives power from the chain and is adapted to interface with the rear wheel hub for driving the rear wheel of the bicycle. Some bicycles are provided with internally geared rear hubs, where a set of gears is arranged to receive power from the cog and drive the rear wheel. In some applications, a bicycle is provided with a CVT at the rear hub to drive the rear wheel.
However, there remains an unfulfilled need for a CVT that is received and supported by the frame members of the bicycle at a location forward of the rear wheel or rear wheel hub. The embodiments of the CVTs disclosed here address this and other needs in the field of continuously variable transmissions.